再上数据分页控件（不用存储过程）

再上数据分页控件（不用存储过程）

 

发布日期：2011年04月04日 星期一 作者:EricHu

 

本篇主要内容如下：

·     概述

·     本分页控件原理。

·     分页控件代码。

·     分页控件使用实例。

 

---

 

概述

在前几篇：我介绍了原创企业级控件库之大数据据量分页控件，这个控件主要是通过存储过程进行数据分页，得到了大家的支持，也给出了许多宝贵的建议，在这儿先感谢各位。同时也让我更有信心进行以后的文章（企业级控件库系列）。

分页对于每个项目来说都有它存在的意义，想起在以前刚刚刚软件开发时，由于刚刚毕业，理论知识雄厚，但实际工作经验欠缺，记得几年前做开发时，数据量很大，要用分页，一开始真不知道如何是好，方法到知道，但速度与稳定性却没有经验。在这儿，我只是起到一个抛砖引玉的作用，以便引起我们在实际工作中要多思考，对同一件事多想几种解决方式，只有这样才能不断提高，同时要学会总结。

这篇我将给大家介绍：不用存储过程，直接用代码来实现数据分页，欢迎大家拍砖，觉得不错的可以推荐下。同时，你要用什么好的想法，也可以与我交流，谢谢。

 

 

本分页控件原理

分页的方法很多，有用存储过程的，有不用存储过程的，还有在C#中用DataGridView的虚拟模式的，目的只有一个，对大数据量进行处理，让用户体验得到提高，软件速度得到提升。本分页控件主要是用了下面的SQL语句，我相信你能看懂的，存储过程分页也是用类似的SQL代码：

 

 1 /*TableName           :表名            如:tbTestData
 2   SqlWhereStatement   :Sql Where表达式 如:where表达式为空
 3   PrimaryKey          :主键            如:UniqueID
 4   PageSize            :分页大小        如:50
 5   pageIndex           :当前页          如:8
 6   OrderField          :排序字段        如:InsetDataTime 
 7 */
 8 
 9 SELECT TOP 50 * FROM tbTestData 
10 WHERE  UniqueID >
11     (
12         SELECT  ISNULL(MAX(id),0) FROM  

           (SELECT  TOP 50 * (8-1) UniqueID  FROM tbTestData  ORDER BY UniqueID)
13     ) 
14 ORDER BY UniqueID 

 

原理就这么简单。

 

 

 

 

分页控件代码

       （一）、实例数据库代码

创建实例数据库。

 

CREATE TABLE [tbTestData](
    [UniqueID] [bigint] NOT NULL,
    [CompanyName] [varchar](200) NULL,
    [CompanyCode] [varchar](50) NULL,
    [Address] [varchar](500) NULL,
    [Owner] [varchar](100) NULL,
    [Memo] [varchar](2000) NULL,
    [InsetDataTime] [datetime] NULL,
 CONSTRAINT [PK_tbTestData] PRIMARY KEY CLUSTERED 
(
    [UniqueID] ASC
)WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON) ON [PRIMARY]
) ON [PRIMARY]

GO

ALTER TABLE [dbo].[tbTestData] ADD  CONSTRAINT [DF_tbTestData_InsetDataTime]  DEFAULT (getdate()) FOR [InsetDataTime]
GO

--生成实例数据
declare @intRowNumber int;
select @intRowNumber = 1;
while @intRowNumber < 1000000
begin
    
    insert into tbTestData(UniqueID,CompanyName,CompanyCode,Address,Owner,Memo)
    values(@intRowNumber,'CompanyName' + cast(@intRowNumber as varchar(2000)),
           'CompanyCode' + cast(@intRowNumber as varchar(2000)),'Address'+ cast(@intRowNumber as varchar(2000)),
           'Owner' + cast(@intRowNumber as varchar(2000)),'Memo' + cast(@intRowNumber as varchar(2000)));    
    select @intRowNumber = @intRowNumber + 1
end

（二）、分页控件代码。

 

namespace DotNet.Controls
{
    /// <summary>
    /// 分页控件（使用代码实现，不用存储过程）
    /// UcPageControlByCode
    /// 修改纪录
    ///     
    ///     2010-01-06 胡勇 修改转到某页由原来的KeyPress方法改为KeyDown，让用户按回车键确认转页，以防止连续绑定两次。
    ///     2011-01-06 胡勇 增加对分页控件的初始化代码:public DataTable InitializePageControl()。
    ///     2011-01-05 胡勇 创建分页控件
    ///     2011-04-02 胡勇 优化代码、减少不必要的私有变量，去掉多余的代码
    ///     
    /// <author>
    ///     <name>胡勇</name>
    ///     <QQ>80368704</QQ>
    ///     <Email>80368704@qq.com</Email>
    /// </author>
    /// </summary>
    [ToolboxItem(true)]
    [DefaultEvent("OnEventPageClicked")]
    [ToolboxBitmap(typeof(UcPageControlByCode), "Images.UcPageControlByCodeIcon.png")]
    [Description("分页控件（使用代码实现，不用存储过程）")]
    public partial class UcPageControlByCode : UserControl
    {
        #region 私有变量
        int recordCount = 0; //记录数
        int pageCount   = 0; //总页数
        int pageIndex   = 0; //当前页
        #endregion

        #region 自定义事件
        /// <summary>
        /// 单击分页按钮(第一页、上一页、下一页、最后页、跳页)时发生
        /// </summary>
        [Category("UcPageControlByCode"), Description("单击分页按钮时发生")]
        public event EventHandler OnEventPageClicked;
        #endregion

        #region 自定义属性
        private int    _pageSize          = 50;             //分页大小
        private string _sqlWhereStatement = string.Empty;   //MsSql Where语句
        private string _sqlConnString     = string.Empty;   //MsSql 数据库连接字符串
        private string _tableName         = string.Empty;   //表名        
        private string _orderField        = string.Empty;   //数据表的排序字段
        private string _primaryKey        = string.Empty;   //数据表的主键
        private string _queryFieldList    = "*";            //字段列表（默认为：*)
        private DataTable _pageTable      = new DataTable();
       
        /// <summary>
        /// 返回当前页码
        /// </summary>
        public int PageIndex
        {
            get
            {
                return pageIndex + 1;
            }
        }

        /// <summary>
        /// 得到或设置分页大小(默认为:50)
        /// </summary>
        [Browsable(true), Category("UcPageControlByCode"), Description("得到或设置分页大小(默认为:50)")]
        public int PageSize
        {
            get
            {
                return _pageSize;
            }
            set
            {
                _pageSize = value;
            }
        }
        
        /// <summary>
        /// SQL语句的Where表达式
        /// </summary>
        [Browsable(false), Category("UcPageControlByCode"), Description("得到或设置SQL语句的Where表达式")]
        public string SqlWhereStatement
        {
            get
            {
                return _sqlWhereStatement;
            }
            set
            {
                _sqlWhereStatement = value;
            }
        }
        
        /// <summary>
        /// 得到或设置SqlServer的连接字符串
        /// </summary>
        [Browsable(false), Category("UcPageControlByCode"), Description("得到或设置SqlServer的连接字符串")]
        public string SqlConnString
        {
            get
            {
                return _sqlConnString;
            }
            set
            {
                _sqlConnString = value;
            }
        }

        /// <summary>
        /// 得到用户单击分页按钮后返回的DataTable
        /// </summary>
        [Browsable(false), Category("UcPageControlByCode"), Description("得到用户单击分页按钮后返回的DataTable")]
        public DataTable PageTable
        {
            get
            {
                return _pageTable;
            }
        }
        
        /// <summary>
        /// 设置或得到与分页控件绑定的表名或视图名
        /// </summary>
        [Browsable(true), Category("UcPageControlByCode"), Description("设置或得到与分页控件绑定的表名或视图名")]
        public string TableName
        {
            get
            {
                return _tableName;
            }
            set
            {
                _tableName = value;
            }
        }
        
        /// <summary>
        /// 设置或得到分页控件排序字段
        /// </summary>
        [Browsable(true), Category("UcPageControlByCode"), Description("设置或得到分页控件排序字段")]
        public string OrderField
        {
            get
            {
                return _orderField;
            }
            set
            {
                _orderField = value;
            }
        }
        
        /// <summary>
        /// 设置或得到分页控件绑定数据表的主键
        /// </summary>
        [Browsable(true), Category("UcPageControlByCode"), Description("设置或得到分页控件绑定数据表的主键")]
        public string PrimaryKey
        {
            get
            {
                return _primaryKey;
            }
            set
            {
                _primaryKey = value;
            }
        }
        
        /// <summary>
        /// 设置或得到分页控件绑定的字段列表(默认为:*)
        /// </summary>
        [Browsable(true), Category("UcPageControlByCode"), Description("设置或得到分页控件绑定的字段列表(默认为:*)")]
        public string QueryFieldList
        {
            get
            {
                return _queryFieldList;
            }
            set
            {
                _queryFieldList = value;
            }
        }
        #endregion

        #region 构造函数
        /// <summary>
        /// 分页控件（使用代码实现，不用存储过程）
        /// </summary>
        public UcPageControlByCode()
        {
            InitializeComponent();
        }
        #endregion

        #region 分页实现相关代码

        #region void SetUcPageControlPars(string connStr, string whereStatement, string tbName, string orderField, string primaryKeyName, string fieldList):给UcPageControlByCode控件传递必需参数
        /// <summary>
        /// 给UcPageControlByCode控件传递必需参数
        /// </summary>
        /// <param name="connStr">连接字符串</param>
        /// <param name="whereStatement">MsSql Where语句 </param>
        /// <param name="tbName">数据表名或视力名</param>
        /// <param name="orderField">排序字段</param>
        /// <param name="primaryKeyName">主键值</param>
        /// <param name="fieldList">字段列表(默认为:*)</param>
        public void SetUcPageControlPars(string connStr, string whereStatement, string tbName
                                       , string orderField, string primaryKeyName, string fieldList)
        {
            if (string.IsNullOrEmpty(connStr.Trim()))
            {
                DialogHelper.ShowErrorMsg("温馨提示：\n无可用的数据库连接！");
                return;
            }
            else
            {
                this.SqlConnString = connStr;
            }
            this.SqlWhereStatement = whereStatement;
            this.TableName = tbName;
            this.OrderField = orderField;
            this.PrimaryKey = primaryKeyName;
            if (!string.IsNullOrEmpty(fieldList.Trim()))
            {
                this.QueryFieldList = fieldList;
            }
        }
        #endregion

        #region DataTable InitializePageControl():初始化UcPageControlByCode
        /// <summary>
        /// 绑定UcPageControlByCode(并返回包含当前页的DataTable)
        /// </summary>
        /// <returns>DataTable</returns>
        public DataTable BindPageControl()
        {
            recordCount       = GetTotalRecordCount();                           //获取总记录数  
            pageCount         = recordCount / PageSize - ModPage();              //保存总页数（减去ModPage()函数防止SQL语句执行时溢出查询范围，可以用存储过程分页算法来理解这句） 
            pageIndex         = 0;                                               //保存一个为0的页面索引值到pageIndex   
            lblPageCount.Text = (recordCount / PageSize + OverPage()).ToString();//显示lblpageCount、lblrecCount的状态   
            lblRecCount.Text  = recordCount.ToString();
                
            if (recordCount <= PageSize)
            {
                txtGoToPage.Enabled = false;
            }
            else
            {
                txtGoToPage.Enabled = true;
            }

            return TDataBind();  
        }
        #endregion

 

        #region 余页计算与总记录数
        /// <summary>
        /// 计算余页
        /// </summary>
        /// <returns></returns>         
        private int OverPage()
        {
            int returnValue = 0;

            if (recordCount % PageSize != 0)
            {
                returnValue = 1;
            }          

            return returnValue;
        }

        /// <summary>
        /// 计算余页，防止SQL语句执行时溢出查询范围   
        /// </summary>
        /// <returns></returns>
        private int ModPage()
        {
            int returnValue = 0;

            if (recordCount % PageSize == 0 && recordCount != 0)
            {
                returnValue = 1;
            }
            
            return returnValue;
        }

        /// <summary>
        /// 计算总记录数
        /// </summary>
        /// <returns>记录总数</returns> 
        private int GetTotalRecordCount()
        {
            int returnValue     = 0;
            string sqlStatement = "select count(1) as rowsCount from " + TableName; 

            if (SqlWhereStatement.Trim().Length > 0)
            {
                sqlStatement = "select count(1) as rowsCount from " + TableName + " where " + SqlWhereStatement;
            }

            SqlDataReader dr = null;
            try
            {
                dr = DbHelperSQL.ExecuteReader(sqlStatement, SqlConnString);
                if (dr.Read())
                {
                    returnValue = Int32.Parse(dr["rowsCount"].ToString());
                }
                
            }
            catch(Exception ex)
            {
                DialogHelper.ShowErrorMsg(ex.Message);
            }
            finally
            {
                dr.Close();
                dr.Dispose();
            }

            return returnValue;
        }
        #endregion

        #region DataTable TDataBind():数据绑定
        private DataTable TDataBind()
        {
            StringBuilder sbSqlStatement = new StringBuilder();
            bool isForward  = pageIndex + 1 > 1;
            bool isBackward = (pageIndex != pageCount);
            btnFirstPage.Enabled = isForward;
            btnPrevPage.Enabled  = isForward;            
            btnNextPage.Enabled  = isBackward;
            btnLastPage.Enabled  = isBackward;            

            if (string.IsNullOrEmpty(SqlWhereStatement.Trim()))
            {
                sbSqlStatement.Append("SELECT TOP " + PageSize + "  " + QueryFieldList + " FROM " + TableName + " WHERE " + PrimaryKey + " NOT IN(SELECT TOP ");
                sbSqlStatement.Append(PageSize * pageIndex + "  " + PrimaryKey + " FROM " + TableName);
                sbSqlStatement.Append(" ORDER BY " + OrderField +" DESC) ORDER BY " + OrderField + " DESC");
            }
            else
            {
                sbSqlStatement.Append("SELECT TOP " + PageSize + "  " + QueryFieldList + " FROM " + TableName + " WHERE " + SqlWhereStatement + " AND " + PrimaryKey + " NOT IN(SELECT TOP ");
                sbSqlStatement.Append(PageSize * pageIndex + "  " + PrimaryKey + "  FROM " + TableName + " WHERE " + SqlWhereStatement + "  ORDER BY " + OrderField + " DESC) ORDER BY " + OrderField + " DESC");
            }

            _pageTable          = DbHelperSQL.Query(sbSqlStatement.ToString(), SqlConnString).Tables[0];
            lblCurrentPage.Text = (pageIndex + 1).ToString();
            txtGoToPage.Text    = (pageIndex + 1).ToString();
            return _pageTable;
        }
        #endregion

        #region 按钮事件代码
        private void btnFirstPage_Click(object sender, EventArgs e)
        {
            pageIndex  = 0;            
            _pageTable = TDataBind();

            if (OnEventPageClicked != null)
            {
                OnEventPageClicked(this, null);
            }
        }

        private void btnPrevPage_Click(object sender, EventArgs e)
        {
            pageIndex--;             
            _pageTable = TDataBind();

            if (OnEventPageClicked != null)
            {
                OnEventPageClicked(this, null);
            }
        }

        private void btnNextPage_Click(object sender, EventArgs e)
        {
            pageIndex++;
            _pageTable = TDataBind();

            if (OnEventPageClicked != null)
            {
                OnEventPageClicked(this, null);
            }
        }

        private void btnLastPage_Click(object sender, EventArgs e)
        {
            pageIndex  = pageCount;       
            _pageTable = TDataBind();

            if (OnEventPageClicked != null)
            {
                OnEventPageClicked(this, null);
            }
        }

        private void txtGoToPage_KeyDown(object sender, KeyEventArgs e)
        {
            if (e.KeyCode == Keys.Enter)
            {
                try
                {                                  
                    if (Int32.Parse(txtGoToPage.Text) > (recordCount / PageSize + OverPage()) || Int32.Parse(txtGoToPage.Text) <= 0)
                    {
                        DialogHelper.ShowWarningMsg("页码范围越界!");
                        txtGoToPage.Clear();
                        txtGoToPage.Focus();
                    }
                    else
                    {
                        pageIndex  = Int32.Parse(txtGoToPage.Text.ToString()) - 1;
                        _pageTable = TDataBind();

                        if (OnEventPageClicked != null)
                        {
                            OnEventPageClicked(this, null);
                        }
                    }
                }
                catch (Exception ex) //捕获由用户输入不正确数据类型时造成的异常    
                {
                    DialogHelper.ShowWarningMsg(ex.Message);
                    txtGoToPage.Clear();
                    txtGoToPage.Focus();
                }
            }
        }
        #endregion

        #endregion
    }
}

 

 

分页控件使用实例

     客户端使用代码如下：

     

 1 using System;
 2 using System.Collections.Generic;
 3 using System.ComponentModel;
 4 using System.Data;
 5 using System.Drawing;
 6 using System.Configuration;
 7 using DotNet.Controls;
 8 using System.Text;
 9 using System.Windows.Forms;
10 using DotNet.Common;
11 using DotNet.WinForm.Utilities;
12 
13 namespace DotNet.WinForm.Example
14 {
15     public partial class FrmUcPageControlByCodeTest : Form
16     {
17         public FrmUcPageControlByCodeTest()
18         {
19             InitializeComponent();
20         }
21 
22         private void FrmUcPageControlByCodeTest_Shown(object sender, EventArgs e)
23         {
24             //初始化方法一
25             //ucPageControlByCode.SqlConnString = ConfigurationSettings.AppSettings["DbConnection"];
26             //ucPageControlByCode.SqlWhereStatement = "1=1";
27             //ucPageControlByCode.TableName = "tbTestData";
28             //ucPageControlByCode.OrderField = "UniqueID";
29             //ucPageControlByCode.PrimaryKey = "UniqueID";
30             //ucPageControlByCode.QueryFieldList = "*";
31 
32             //初始化方法二
33             ucPageControlByCode.SetUcPageControlPars(ConfigurationSettings.AppSettings["DbConnection"], "1=1", "tbTestData",
34                 "UniqueID", "UniqueID", "*");
35             DataTable dtTest = new DataTable();
36             dtTest = ucPageControlByCode.BindPageControl();
37             ucDataGridView.DataSource = dtTest;
38 
39             //绑定查询项
40             Dictionary<string, string> dicListQueryItems = new Dictionary<string, string>();
41             foreach (DataColumn dc in dtTest.Columns)
42             {
43                 dicListQueryItems.Add(dc.ColumnName, dc.DataType.ToString());
44             }
45             ucCombinQuery1.SetQueryItems(dicListQueryItems);
46         }
47 
48         private void ucDataGridView_DataBindingComplete(object sender, DataGridViewBindingCompleteEventArgs e)
49         {
50             gbMain.Text = "当前共:" + ucDataGridView.Rows.Count.ToString() + "条数据。";
51         }
52 
53         private void ucPageControlByCode_OnEventPageClicked(object sender, EventArgs e)
54         {
55             ucDataGridView.DataSource = null;
56             ucDataGridView.DataSource = ucPageControlByCode.PageTable;
57         }
58 
59         private void ucCombinQuery1_OnQueryClicked(object sender, EventArgs e)
60         {
61             try
62             {
63                 Splasher.Show(typeof(FrmSplash));
64                 Splasher.Status = "正在查找数据，请稍等...";
65                 System.Threading.Thread.Sleep(450);
66                 ucDataGridView.DataSource = null;
67                 ucPageControlByCode.SqlWhereStatement = ucCombinQuery1.QueryExpression; //指定查询表达式
68                 ucDataGridView.DataSource = ucPageControlByCode.BindPageControl(); //绑定DataGridView
69             }
70             catch (Exception ex)
71             {
72                 ucPageControlByCode.SqlWhereStatement = "1<>1";
73                 ucDataGridView.DataSource = ucPageControlByCode.BindPageControl(); //绑定DataGridView
74                 Splasher.Status = ex.Message;
75                 System.Threading.Thread.Sleep(1000);
76             }
77             finally
78             {
79                 System.Threading.Thread.Sleep(100);
80                 Splasher.Status = "查找完毕...";               
81                 Splasher.Close();                
82             }
83         }
84     }
85 }

 

     最后的效果如下：